Portable sawmill

ABSTRACT

A portable sawmill with lateral and longitudinal stability which includes first and second rectangular end frames, each end frame including two horizontal and two vertical members, longitudinal, horizontal rails slidably connected by brackets to corresponding first and second vertical members, first and second winding assemblies, each winding assembly includes bearings journalling an upper one of the horizontal members, a handle to rotate the upper horizontal frame member, an idler wheel located at a lower end of each of the vertical frame members, and a flexible joining connection for each bracket, the flexible joining connection is engaged about the respective upper frame member and a respective idler wheel and connected at both ends to the respective bracket to move the bracket in both directions up and down the respective vertical frame member to thereby move the rails.

FIELD OF THE INVENTION

This invention relates to a portable sawmill with improved lateral andlongitudinal stability

BACKGROUND OF THE INVENTION

A timber sawing device comprising a single circular sawblade, whichpivots through 90° to act in both the horizontal and vertical planes, isknown. As is known, this sawblade is mounted together with an engine ona laterally movable carriage which in turn is mounted on alongitudinally movable cross-bed which may travel along two railsbetween which the operator has access. Again, as is known, these railshave been mounted on end frames located in a predetermined position andthe rails have been manually and independently raised and lowered at thetwo support points on each end frame.

One object of the invention is to provide a portable sawmill havingimproved stability of the frame.

Another object of the invention is to provide a portable sawmill withimproved operation and stability of the saw means, ease of erection,assembly and operation, for example, by a single operator even in roughconditions.

BRIEF SUMMARY OF THE INVENTION

Broadly in one aspect of the invention there is provided a portablesawmill with lateral and longitudinal stability which comprises:

(a) first and second end frame means;

(b) a pair of longitudinal rails extending between the first and secondend frame means;

(c) bracket means for slidably connecting said rails to said first andsecond end frame means;

(d) moving means on said first and second end frame means, said movingmeans connected to said bracket means for adjustably moving said railsin unison between upper and lower positions on the end frame means andfor retaining said rails in an adjusted position; and

(e) carriage means for a pivotal sawblade mounting and prime mover, saidcarriage means engageable with said rails and longitudinally movablethereon.

Preferably, brace means are connected to an upper region of one or bothvertical members of the end frames, the means of connection is such thateach brace means may be altered in attitude with respect to itsrespective vertical member to provide lateral support to the sawmill orto align the sawmill with a log, the brace means being adjustable inlength.

In a preferred form each bracket comprises:

a bracket body;

support means adapted to hold a rail; and

sliding means adapted to fit a vertical member and permit the bracketbody to be moved up and down the vertical member.

The sawmill further includes a rail supporting means comprising:

(a) a vertically extending braced support; and

(b) a sleeve adapted to extend at least partially around the bracedsupport and movable therealong,

wherein the sleeve is attachable to a rail whereby the rail and hencethe sawmill may be supported.

The sawmill preferably further includes a drive means which comprises:

an engine having a driveshaft,

the centerline of the driveshaft being mounted below and as close aspossible to the axis through which a sawblade forming part of thesawmill pivots.

Still further, the sawmill includes movement control means whichcomprises:

a resilient elbowed strut adapted to travel from a first elbowedposition to a second elbowed position through a position in which thestrut is straight,

the strut connecting an engine mount to a mount for a saw means througha pivot point,

wherein a rotational force applied to the strut straightens the strutand then rotates it through center whereby the saw means may take up twostable positions at right angles to each other and travel speed of thestrut is hydraulically controlled between the two stable positions.

According to a second broad aspect, there is provided a portable sawmillincluding:

(a) first and second substantially rectangular end frames, each endframe comprising two horizontal and two vertical members;

(b) separate rails extending longitudinally relative to the end frames,each rail being slidably connected by means of a bracket to respectiveof said vertical members of the first and second end frames;

(c) brackets for slidably connecting said rails to corresponding firstand second ones of said vertical members;

(d) first and second winding means in combination with respective firstand second ones of said uppermost horizontal member;

(e) an idler wheel located at a lower end of each vertical member;

(f) flexible joining means for connecting each bracket with therespective winding means and the respective idler wheel in such a mannerthat positive up-and-down movement in unison of the rails at each endframe is achieved to adjust and retain in an adjusted position the railsat each end frame; and

(g) a carriage for a prime mover and saw blade mounting movablyengageable with said rails.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following more detailed description of one embodiment of theinvention, reference will be made to the accompanying drawings in which:

FIG. 1 is an isometric view from one side of the framework in the set-upposition;

FIG. 2 is a similar view to FIG. 1 but refers to the operating positionwith rails added and brace means turned 90°;

FIG. 3 is a similar view to FIG. 2 with the addition of a support meansfor an engine and saw means;

FIG. 4 is a similar view to FIG. 3 with the addition of the engine andsaw means;

FIG. 5 is a front view of an end frame showing the position of windingmeans;

FIG. 6 is a side view of the end frame of FIG. 5;

FIG. 7 is a top view of the support means together with the saw meansand engine;

FIGS. 8 and 9 are successive end views of the saw means and engineillustrated in FIG. 7 a illustrating the use of a strut means;

FIG. 10 is a similar view to FIG. 2 but showing the use of a brace meansin connection with a rail; and

FIG. 11 is a side view of the brace means illustrated in FIG. 10.

DETAILED DESCRIPTION OF THE INVENTION

The "flexible joining means" referred to in the specification and claimsmeans such things as rope (natural, synthetic or wire) and chains.

Turning to the drawings, a rectangular framework is indicated generallyby numeral 10. The framework includes rectangular end frames 11 and 12.Each end frame comprises upper and lower members 13 and 14 respectivelyand side members 15 and 16 respectively. In FIG. 1 a telescopic bracemeans 17 is shown propping each end frame in a substantially uprightposition. Being telescopic the length of the brace means 17 can beadjusted.

One end of the brace means 17 is coupled to the side member 16, whilethe other end engages with the ground. The telescopic brace means 17 areshown as lying in a plane substantially at right angles to the plane ofthe end frame. Brace means 17 thus provide lateral support whileassembling the mill.

Side members 15 and 16 are respectively fitted with brackets 18 and 19which are slidable along the length of the side member. As can be seenin FIG. 1, each bracket has a ledge on which a rail (as hereinafterdescribed) can be engaged. A winding means 20 shown associated with theupper member 13 and side member 15 is provided to control the slidingmovement of the brackets 18 and 19 as will be hereinafter described.

In FIG. 2, longitudinal rails 21 and 22 are shown as spanning the sidemembers 15 and 16 of the end frames 11 and 12. The longitudinal rails 21and 22 are engaged with the slidable brackets 18 and 19. Each side railis accordingly adjustable up or down (as indicated by the arrows in FIG.2) by movement of the slidable brackets 18 and 19 on the side members 15and 16, respectively.

In FIG. 2 the brace means 17 are shown as located in the operatingposition such as to provide lateral support while sawmilling. Asillustrated the brace means 17 have been moved (the coupling of the endof the brace means 17 to the side member 16 being such as to permitthis) so that the brace means 17 basically lies in the plane of the endframe. As indicated by the arrows in FIG. 2, the position of the bracemeans can be moved to achieve the best bracing position. When inposition the lower end of the brace means 17 is firmly engaged with theground by a pinning means P shown at the ground engaging end of thebrace means.

In FIG. 3 a support means or frame 23 is shown as spanning between thelongitudinal rails 21 and 22. This support means provides a carriage foran engine and saw means combination 25 (see FIG. 4). Wheels 24 areprovided at each end of the support frame 23 whereupon the support frame23 is movable on the side rails 21 and 22 in a longitudinal directionrelative to the frame 10 as shown by the arrows in FIG. 3. Thus, thesupport frame 23 can be moved along the rails toward or away from therespective end frames 11 and 12.

In FIG. 4 there is shown a further support frame 23a which is mounted bythree wheels 74 so that it is movable longitudinally relative to thelong side of support frame 23. AS will hereinafter be described, thissecond movable frame 23a supports the engine and saw means combination25. Thus, by a combination of the movement of support frame 23 alongrails 21 and 22 and support frame 23a relative to support frame 23, theposition of the engine and saw means combination 25 relative to frame 10can be readily adjusted.

Turning now to FIGS. 5 and 6, a more detailed illustration of thewinding means 20 is provided, this being shown in combination with endframe 11.

As illustrated the upper member 13 is provided with a stub axle at oneend which is journalled in bearing 131 mounted with the upper end ofside member 16. The upper member 13 is further journalled in a bearing132 provided at the upper end of side member 15. The end of the uppermember 13 engaged in bearing 132 extends beyond the bearing and isprovided with a handle H.

Accordingly, by applying a rotational movement to the handle H the uppermember 13 can be rotated.

Flexible joining means 40 (which for ease of convenience willhereinafter be referred to as "rope 40") is shown wrapped around therotatable upper member 13 adjacent each of bearings 131 and 132. Rope 40is attached to a first lug 41 on slidable bracket 18. The other end ofrope 40 runs around idler wheel 42 located at the lower end of sidemember 15 to a second lug 43 attached to and positioned about halfway upslidable bracket 18. Rope 40 adjacent bearing 131 is similarly coupledwith slidable bracket 19.

Thus, by rotating handle H and thereby upper member 13, the slidablemembers 18 and 19 can be simultaneously caused to raise or lowerrelative to the direction in which handle H is rotated. Theconfiguration is such that ropes 40 pull the sliding members 18 and 19down when the handle H is rotated for downward movement. Thus, thesliding members 18 and 19 do not move down simply under gravity.

FIG. 5 shows in more detail the mounting of the side rails 21 and 22with brackets 18 and 19, respectively. Referring to rail 21, it will beseen that the rail is of substantially rectangular cross-section withthe lower end thereof resting on ledge 70 of bracket 18. Disposed aboveledge 70 and also above the upper edge of rail 21 is a projection orland 71 with which lug 41 is engaged. Threaded through land 71 is alocking bolt B which has its lower end engaging with the upper surfaceof rail 21 to provide a downward force to ensure that the rail 21 islocked in position on ledge 70. As shown ledge 70 has a lip at its outerend to ensure rail 21 is firmly held in place.

As also can be seen in FIG. 5, each wheel 24 is mounted by an axleprojecting from a flange 72 (of an angle piece--see FIG. 7) extending upfrom the corner of support frame 23. Wheel 24 is preferably grooved andengages with the edge of a substantially L shaped rail 73 mounted to theupper edge of side rail 21.

FIG. 5 also shows that each of sliding members 18 and 19 includes asleeve 92 which is slidably engaged on the side member 15, 16. Sleeve 92is of a significant length being longer than the depth of rail 21, 22.Projection 71 is attached to the upper end of the sleeve 92.

As can be seen in FIG. 6, sliding members 18, 19 also extend well beyondeach side of the sleeve 92 and a brace 93 extends from the lower end ofsleeve 92 to each outer end of the ledge 70.

As can be more clearly seen in FIG. 7, support frame 23a is movablymounted by what can be termed a tricycle carriage, namely two wheels 74running (in a similar manner to wheels/rails 24 and 73) on a rail 75which extends the full length of the long side of support frame 23.Extending for nearly the full length of the other long side of supportframe 23 is a further rail 75 on which a single wheel 74 associated withside member 76 of frame 23a is engaged. As can also be seen in FIG. 7,one of the wheels 74 is mounted with an extension 76a of the other sidemember 76 of frame 23a.

As can be seen in FIGS. 7, 8 and 9, motor 50 is suspended from supportframe 23a. A brace 77 extends from side member 78 of the support frame23a and engages with a base or mounting portion 79 of motor 50. Brace 77provides resistance against movement of motor 50 as a consequence oftorque of the motor during operation.

Motor drive shaft 80 has mounted thereon a belt pulley 81 about whichbelt(s) 52 extend to pulley wheel 83 mounted on shaft 84a of a drivetransfer 84 and with which is mounted a sawblade 57.

The driver transfer 84 is carried by a sawblade spindle mounting 86which is a generally z-shaped member as viewed in FIG. 7 pivotallycoupled at one end at 88 to side member 76 of support frame 23a. An arm89 is attached to the other end of the z-shaped member 87. This arm 89is in turn coupled via pivot mounting 90 to the opposite side framemember 76.

An oil fitted gas strut 53 has the body portion thereof pivotallymounted at 91 to side member 76 while the piston rod 54 is pivotallymounted at 55 to a connecting arm 56 joined to arm 89 of the sawbladespindle mounting 86.

FIG. 7 shows the sawblade 57 in a substantially horizontal position,i.e., it is substantially parallel to the plane of support frames 23 and23a. This is the configuration as shown in FIG. 8. However, as willhereafter be explained, the spindle mounting 86 can be caused to pivotabout its pivots 88 and 90 in the direction as shown in FIG. 8 so thatthe sawblade 57 can be moved to a substantially vertical position asshown in FIG. 9.

Turning to FIGS. 10 and 11, a rail support 60 is supported by asecondary prop 61. A sleeve means 62 joins support 60 to rail 21. Thissleeve means 62 is connected to rail 21 by bolt 63. A hole 64 isindicated in the other rail 22 and accommodates a bolt similar to 63 tothereby mount a support 60. A spike 65 is positioned at the lower end ofbrace support 60 to assist its placement in the ground. Similarly, aspike 65a or similar is used to engage the end of the prop 61 whichengages with the ground. This support 60 and prop 61 provide a furtherbracing to the rails 21 and 22 to thereby further assist in rigidifyingthe frame 10.

As can be seen in FIGS. 8 and 9, the low mounting of engine 50 (andthereby drive shaft 80) relates to the desirability perceived by theinventor of keeping the center of gravity of the engine close to wherethe saw 57 engages the timber. Consequently, the center line of thedrive shaft 80 is mounted below and as close as possible to the axisthrough which the sawblade spindle mounting 86 pivots about the pivotmounts 88 and 90.

The strut 53 with connecting link 56 forms a resilient elbowed strutadapted to travel from a first position, e.g., FIG. 8 to a secondposition (e.g., FIG. 9) through a position in which the strut isstraight. Thus, a rotational force applied to the strut about pivot 91causes the strut to move from a position to a straight position and thenthrough center. Consequently, the sawblade spindle and hence thesawblade 57 can be moved to take up two stable positions at right anglesto each other. The speed of travel between the two stable positions iscontrolled hydraulically by the oil fitted gas strut, the oil modulatingthe speed of operation of the piston coupled to rod 54.

Preferably, a self-energizing brake is combined with one or each of thewinding arrangements 20. The self-energizing brake is constructed so asto store energy which may be used to provide braking power. Thus, such abrake when combined with the winch or winding arrangement controls theoperations of the winch and thereby the upward and downward movements ofthe rails 21 and 22 when such are being adjusted in position relative tothe end frames 11 and 12.

The claims defining the invention are as follows:
 1. A portable sawmillwith lateral and longitudinal stability, comprising:(a) first and secondsubstantially rectangular end frames, each end frame comprised of spacedvertical frame members, a lower ground engaging frame member and anupper frame member spaced from the lower frame member; (b) a braceconnected to each end frame to laterally support the respective endframe; (c) a pair of longitudinal rails mounted on correspondingvertical frame members of the first and second end frames; (d)individual brackets slidably mounted on each of the vertical framemembers for slidably connecting individual said rails to said first andsecond end frames such that the rails are extendable beyond the endframes, each of the brackets being unconnected with other said brackets;(e) first and second winding assemblies on the respective first andsecond end frames, each winding assembly including bearings journallingsaid upper frame member, a handle to rotate the upper frame member, anidler wheel located at a lower end of each said vertical frame member,and a flexible joining connection for each bracket, each joiningconnection being engaged about the respective upper frame member and arespective idler wheel and connected at both ends to the respectivebracket to move the bracket in both directions up and down therespective vertical frame member to thereby adjustable move therespective ends of said rails in unison between upper and lowerpositions on the respective end frames and for retaining said rails inan adjusted position; and (f) a first carriage engageable with saidrails and longitudinally movable thereon; and (g) a pivotal saw bladeand a prime mover therefor mounted to said first carriage and moveablethereon laterally relative to said rails.
 2. A portable sawmill asclaimed in claim 1, wherein each said brace is connected to each saidrespective end frame with a connection connected to an upper region ofthe respective end frame, each brace having an attitude which isadjustable such that each brace is movable with respect to itsrespective end frame to selectively provide longitudinal or lateralsupport to the sawmill.
 3. A portable sawmill as claimed in claim 1,further comprising a rail brace including:(a) a vertical extendingsupport; (b) a lateral brace member connected to the upper end of thesupport and adapted to engage the ground; and (c) a sleeve adapted toextend at least partially around the support, the sleeve having anattachment to connect to one of said rails.
 4. A portable sawmill asclaimed in claim 1, wherein said prime mover includes a motor and amotor drive shaft, the drive shaft having a center line which isadjacent to but generally beneath a pivotal mounting axis of said sawblade.
 5. A portable sawmill as claimed in claim 1, further comprising apivot control assembly, comprising:an elbowed strut having a first armpivotally connected to an extendable and retractable second arm which isbiased to an extended position, the strut connecting said carriage and amounting for said saw blade, the strut being movable from one angularrelationship of the first and second arms to another angularrelationship to move an axis of the saw blade mounting between positionsof the saw blade at right angles to each other.
 6. A portable sawmill asclaimed in claim 1, further comprising a second carriage mounted formovement on the first carriage in a direction transverse to the rails,and said second carriage mounting said prime mover and a mounting forsaid saw blade.
 7. A portable sawmill as claimed in claim 1, whereineach said brace is adjustable in length.
 8. A portable sawmill asclaimed in claim 1, wherein each bracket comprises:a sleeve engaged onthe respective vertical frame member; a rail support carried by thesleeve and including a ledge for holding the respective rail; and firstand second lugs to receive the ends of the flexible joining connection.9. A portable sawmill as claimed in claim 1, wherein said first carriageis longitudinally movable with said rails through said end frames so asto extend beyond said end frames.